共查询到20条相似文献,搜索用时 93 毫秒
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碳酸钙晶须用表面改性剂Si-69、硬脂酸钠、钛酸酯偶联剂NDZ101进行表面处理,并用于天然橡胶(NR)的补强。结果表明,表面处理后碳酸钙晶须的表面性能提高,与NR的界面作用增强,对NR起到明显的补强作用。表面处理后碳酸钙晶须的加入使改性碳酸钙晶须/NR复合材料的损耗因子tan艿降低,热稳定性提高。其中以Si-69改性碳酸钙晶须补强效果最优,Si-69改性碳酸钙晶须/NR复合材料300%定伸应力、拉伸强度、撕裂强度比未改性的分别提高36.9%、34.2%、24.7%。 相似文献
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本研究以苯乙烯(St)、丙烯酸丁酯(BA)和丙烯酸异辛酯(EHA)为主要单体,通过核壳乳液聚合法制备得到阻尼涂料乳液,并探究核层与壳层玻璃化转变温度对于乳液损耗因子(tanδ)的影响,结果表明核层玻璃化转变温度为-20℃时,壳层玻璃化转变温度由30℃升高至50℃,损耗因子峰值出现的位置往低温区移动;当壳层玻璃化转变温度为40℃时,核层玻璃化转变温度由-30℃升高至-10℃,Tanδ-Temperature曲线由部分重叠的宽而矮的双峰逐渐过渡为窄而高的单峰,损耗因子峰值逐渐增大。采用本研究合成的乳液S1制备得到的阻尼涂料具有优越的综合性能。 相似文献
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研究了硅烷偶联剂Si-69在NR/BR共混胶硫黄硫化体系中对白炭黑的补强作用效果。结果表明:当Si-69的用量为白炭黑用量的1/6左右时,硫化胶的拉伸强度、300%定伸应力具有最大值;Si-69的加入,使硫化胶在常温下的损耗因子(tanδ值)变小。 相似文献
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直接酯化法合成了一系列聚对苯二甲酸乙二酯(PET)-间苯二甲酸双羟乙酯磺酸钠(SIPE)-聚乙二醇(PEG)共聚酯,以差示扫描量热分析法(DSC)研究了这些共聚酯及纯PET的熔融和结晶过程,并利用万能材料测试仪研究了纤维的力学性能。试验结果表明:加入SIPE和PEG后,共聚酯熔点(Tm)、玻璃化转变温度(T)g降低;随着PEG相对分子质量的增大,PET共聚酯的Tg、冷结晶温度(Tc)c、Tm、结晶温度降低(T)c,纤维的断裂强度和初始模量下降,断裂伸长率增加。 相似文献
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自行合成了端羟基的热致性聚酯液晶(PHET),采用原位复合的方法制备了热致性聚酯液晶(PHET)/酚醛树脂(PF)原位复合材料,研究了PHET的用量对PHET/PF原位复合材料的冲击强度、弯曲强度、动态力学性能、热性能等的影响。结果表明,PHET的加入可以提高PHET/PF原位复合材料的力学性能、动态力学性能和热性能,当PHET质量分数为7.5%时,原位复合材料的冲击强度、弯曲强度和玻璃化转变温度(Tg)分别提高了44.69%、44.68%和22.9℃。在200℃时,PHET/PF共混物中液晶丝状织态结构明显且分布连续。 相似文献
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JOHN P. HOWE 《Journal of the American Ceramic Society》1952,35(11):275-283
The structure, thermal properties, electrical characteristics, and mechanical behavior of graphite are reviewed and the highly anisotropic character of graphite crystals is emphasized. The interesting properties of graphite are due in large measure to the strong semimetallic bonds between carbon atoms in plane layers and to the relatively weak binding between planes. Details of its structure are due in part to the Frank dislocation mechanism for growth of crystals. Thus graphite has a low vapor pressure and approximately two-dimensional electrical and thermal conductivity. It is easily deformed in slip on the basal plane, but in polycrystalline form it is relatively strong at high temperature. Its lamellar nature is emphasized by its reaction with alkali metals and bromine. 相似文献
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纳米材料的性质 总被引:24,自引:0,他引:24
编者按:纳米材料是近年来科学上的一项重大发现,已成为当今许多学科的研究热点.纳米材料是指颗粒尺寸在纳米量级(1~100 nm)的超细材料,其尺寸大于原子簇而小于通常的微粉,处在原子簇和宏观物体交界的过渡区域.正如美国著名物理学家、诺贝尔奖获得者R.P.Feynman所言:"如果我们得以在细微尺度上控制事物的话,毫无疑问,这将使材料所具有的物性范围大为扩充."纳米材料在结构、光电和化学性质等方面的诱人特征,正引起材料科学家的浓厚兴趣.纳米材料科学是凝聚态物理、胶体化学、配位化学、化学反应动力学、表面、界面等学科的交叉学科,是现代材料科学的重要组成部分.纳米材料的发展对于人们进一步认识固体材料的本质结构性能具有十分重要的价值,科学家们把这种材料誉为"21世纪最有前途的材料".因此,本刊拟开辟"纳米材料专栏",以期对纳米材料的性能、研制方法以及在各个领域的应用与发展作较为全面、系统的报道.欢迎专家学者投稿进行专题介绍与评述,也欢迎读者来信来函提出意见和建议. 相似文献
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Carbopyroceram is obtained by directed crystallization in pyrolysis of hydrocarbons. The high physicochemical, strength, elastic,
surface, and other properties make it applicable for making artificial heart valves that must function for many years. Experiments
have shown that carbon, which constitutes the base of carbopyroceram, has a normal electrochemical potential and a surface
energy close to those of the living tissue of an organism, which determines its biological compatibility. The present paper
concerns the strength, elastic, thermophysical, x-ray diffraction, and electrical properties of carbopyroceram. The parameters
of the properties are needed for calculating the service time of endogenic prostheses. 相似文献
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用DDVⅢEA型动态粘弹谱仪和UJ40型Izod冲击实验机对硝胺和硝基胍两种火炮发射药的动态粘弹性和冲击断裂性能进行了研究,从理论和实验两方面探讨了火炮发射药动态粘弹性和冲击断裂性能的关系,指出:冲击断裂韧性Gc随动态贮能模量的增加而减小,随β次级转变时tanδ峰值的增加而增加;根据时温等效原理,可以预测火炮发射药身管武器膛内超高速动态条件下应用时的动态力学特性,对进一步改进这两类材料的力学性能具有重要意义。 相似文献
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Copolymers including hydroquinone and vinylpyridine units have been prepared by the copolymerization reaction of quinones with vinylpyridines. By-products of these reactions are the homopolymer and the hydroquinone form of the respective quinone. It has been established that in the formation of the copolymers, the weak intermolecular complexes of quinones (Qs) with vinylpyridines (VPs) have an essential contribution. The kinetics of Q copolymerization with VP in the presence of triethylamine has been investigated. The values of the reaction order based on the components, the rate constants and activation energies of the copolymerization processes have been determined. The copolymers prepared are soluble in polar organic solvents, have high reactivity for electron exchange, and possess antioxidant, antihypoxemic and antistatic properties. © 1997 SCI 相似文献